Electrode mounting for neon tubes



A ril 4, 1939. F KASPAR 2,153,375:

ELECTRODE MOUNTING FOR NEON TUBES Filed Oct. 10, 1938 Patented Apr. 4,1939 PATENT OFFICE ELECTRODE MOUNTING FOR NEON TUBES Frank Kaspar,Cicero, Ill., assignor to General Scientific Corporation, Chicago, 11].,a corporation of Illinois Application October 15, 1938, Serial No.234,147

6 Claims.

The present invention relates to gaseous conduction devices, and moreparticularly to the mounting of electrodes in the ends of gaseousconduction tubes which are utilized for display signs and the like.

In the past there has been considerable difficulty in the processing ofthe tubes because of the fact that the lead-in wires often fail, due tothe extremely high heat in the processing and, if the electrode issupported by the lead-in wires, the hot electrode strikes the glass ofthe tube and breaks it. It is also important in shipping and inoperation to have the electrodes so mounted that they may be preventedfrom contacting the tube walls. Reentrant stems on the glass tube itselfand various other devices have been employed to properly support theelectrode. It has also been proposed to enclose the electrode in a glassshield to prevent it from contacting the glass, and other practicesinclude the provision of some sort of insulating ring, such as a ring ofglass beads or a collar adjacent both ends of the electrode, the beadsor collar serving the purpose of supporting the electrode while they inturn are supported by the wall of the glass tube.

It is the purpose of the present invention to provide a more simple,economical and effective supporting means by which the electrode can becarried on the lead-in wire and be prevented from engaging the walls ofthe surrounding tube.

The features and advantages of the present invention will appear morefully as the description proceeds, reference being had to theaccompanying drawing wherein a preferred form of the invention is shown.It is to be understood, however, that the drawing and description areillustrative only, and are not to be taken as limiting the inventionexcept insofar as it is limited by the claims.

In the drawing, Fig. 1 is a view in side elevation of the electrode andof a gaseous conduction tube embodying my invention;

Fig. 2 is a longitudinal section taken on the line 22 of Fig. 1, and

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2.

Referring now to the drawing, the numeral 5 designates the electrode endof a gaseous conduction tube. An electrode 5 is mounted in the tube 5.The electrode 6 has one end closed, as indicated at I. This end of theelectrode is utilized to support the electrode in the tube 5. A doubledlead-in wire 8 is employed, the lead-in wire being fastened at 9 to theend of the elec- (Cl. 176-426) I trode 6 and having its leg portions land ll spread apart at a short distance from the end of the electrode 8.

A cup-shaped insulating member I2 fits over the rounded end of theelectrode 6 and is held in place by the lead-in wire 8. The member 12has an opening l3 through which the lead-in wire extends, and the memberI2 is supported by the lead-in .wire, due to the spreading of theportions l0 and ll. Themember I2 is slightly larger in internal diameterthan the external diameter of the electrode 6. It covers only about A ofthe exterior surface of the electrode 6. The exterior surface of themember I2 is cylindrical between the points It and I (see Fig. 2) andthe exterior diameter of the member I2 is such that this cylindricalportion fits loosely inside the tube 5. The amount of play between thetube and the member I2 is sumcient to avoid binding, due to differencesin expansion and contraction. However, the cylindrical part of themember l2 prevents tipping of the member in the tube an amountsufiicient to permit the electrode 6 to engage the tube 5. This isclearly shown in Figs. 2 and 3, wherein the limit of movement of theelectrode 5 toward the glass tube 5 is illustrated.

It is believed to be evident that the present invention provides a meanswhereby the electrode is held away from the wall of the tube, evenduring bombardment and processing of the tube, whether or not thelead-in wires fail. It is, of course, evident to those skilled in theart that the member I2 also provides efiective protection for thelead-in wires by substantially insulating the lead-in wires againstdischarge exteriorly of the electrode. The spaces between the member l2and the tube 5 and between the member I2 and the electrode 6 are so'small as to substantially provide mean free path insulation.

From the above description it is believed that the construction andadvantages of this device will be readily apparent to those skilled inthis,

art. Having thus described my invention, what I claim as new and desireto secure by Letters Patent is:

1. The electrode end of a gaseous conduction tube, comprising a lengthof glass tubing closed at one end, a tubular electrode in said tube, alead-in wire having two branches which are secured to said electrode anda cup-shaped insulat ing member covering the lead-in wire end of theelectrode, said cup-shaped member being held in position on theelectrode by said branches of the lead-in wires.

wire fixed to one end oi said 2. The electrode end oi a gaseousconduction tubc,alengthoi'glasstubingclosedatoneendatubula'relectrodeinsaidtubaa lead-in wire having two brancheswhich are securedtosaidelectrodeandacup-shapedinsulating member coveringthe lead-in wire end of the electrode, safi cup-shaped member being heldin position on the electrode by said branches of the lead-in wires, saidcup-shaped member having-a cylindrical portion the exterior and interiorsurfaces of which loosely fit' the corresponding suri'aces of the tubingand electrode respectively, whereby tilting of the electrode intoengagement with the tubing is avoided. a

3. The electrode, end oi a gaseous conduction tube, comprising a length01' glass tubing closed at one end. a tubular electrode in said tube, a

lead-in wire having two branches which are secured to said electrode anda cup-shaped insulating member covering the lead-in wire end of theelectrode, said cup-shaped member being held in position on theelectrode by said branches of the lead-in wires, said cup-shaped memberhaving an opening in the base thereof throughwhich the branches oi thelead-in wire extend, said branches being turned out directly outside ofsaid. opening.

4. In a gaseous conduction tube of the character described, a tubularelectrode, a lead-in electrode and supporting said electrode, and ahollow insulating member mounted on said lead-in wire and fittingloosely over the adiacent end of the electrode, said member having itsexterior suriace in close proximity to the tube wall whereby to preventtilting of the electrode into contact with the tube wall.

5. In a gaseous conduction tube oi. the character described,'a tubularelectrode, a lead-in wire fixed to one end of said electrode andsupporting said electrode, and a hollow insulating member mounted onsaid lead-in wire and fitting loosely over the adjacent end of theelectrode. said memher having its exterior surface in close proximity tothe tube wall whereby to prevent tilting of the electrode into contactwith the tube wall. said insulating member being apertured to receivethe lead-in wire and said lead-in wire being bent to hold the insulatingmember in place.

6. The electrode end of a gaseous conduction tube, comprising a lengthof glass tubing closed FRANK KASPAR.

